Electrical capacitance tomography (ECT) techniques have been developed to visualize industrialprocesses with dielectric materials. Phase sensitive demodulation is a key part of ECT system to improve speed and accuracy. Methods of demodulation are demonstrated in this paper, including analogue and digital methods.
The problems about applying digital quadrature demodulation in ECT were simulated by SIMULINK. Validation shows that the digital phase sensitive demodulation is complete enough to meet the requirements of ECT system in accuracy and speed.